1. THE NEMERTES.2. THE NEREIS.
CHAPTER VII
STARFISHES
STARFISHES’ LEGS
OF course you know starfishes very well indeed by sight, for they are flung up in numbers on the beach by almost every tide. But I wonder if you know where their legs are!
Perhaps you did not know that they have any legs. But they have hundreds and hundreds of them. Only, instead of keeping their legs outside their bodies, as we keep ours, starfishes always keep them inside, and poke them out through little holes in the skin when they are required for use.
If you want to see the legs of a starfish, you can very easily do so. First of all, you must catch a starfish, and make quite sure that he is alive. You can easily find out that by picking him up. If his rays are quite limp and flabby, and hang downwards from the disc, or middle part of his body, so that they look rather like the legs of a table, he is dead, and you can throw him away. But if they stand out stiffly he is alive. Then just put him into a pool of sea-water, and wait. After a few minutes you are almost sure to see that he is moving. Very slowly he begins to glide along the bottom of the pool. If he comes to a stone, he glides over it. If he comes to a rock, he glides up it. Then, if you suddenly snatch him out of the water, and turn him upside down, you will see his legs—little white fleshy objects waving about all over the lower surface of his body. And if you look at them through a good strong magnifying-glass, you will see that each one has a kind of little cup at the end of a slender stem.
Now this cup is really a sucker, very much like the suckers of a cuttle, only of course a great deal smaller. And the starfish walks by pushing one or two of its rays forward, taking hold of the ground with the suckers underneath them, and then pulling up the hinder rays and taking hold with the suckers underneath those, and so on over and over again.
PLATE XXXV
THE FIVE-FINGER STARFISH (1)
This is by far the commonest of all the starfishes. You can seldom walk for even a short distance along the shore without seeing it. And no doubt you might think that it must be a very harmless creature indeed, for it does not look as if it could injure any other animal in any way at all. Yet it is really a creature of prey, and feeds upon shell-bearing molluscs, such as small bivalves, which it always swallows whole. Then, when it has digested their bodies, it returns their empty shells through its mouth. And it can even eat such big creatures as mussels and oysters. Indeed, starfishes are the very worst enemies of the oyster-beds, and in one fishery alone, on the coast of North America, they are said to destroy more than ten thousand pounds’ worth of oysters every year!